Pneumatic impact-molding machine with shuttle hopper



March 18, 1969 H. E. FELLOWS PNEUMATIC IMPACT-MOLDING MACHINE WITHSHUTTLE HOPPER Filed July 30, 1965 Sheet INVENTOR. A AKAIJ'IIV 91m!March 18, 1969 PNEUMATIC Filed July 39, 1965 H. E. FELLOWS 3,433,285

IMPACT-MOLDING MACHINE WITH SHUTTLE HOPPER Sheet 3' of ll ffdR/YEYLMarch 1-8, 1969 H. E. FELLOWS 3,433,285

PNEUMATIC IMPACT-MOLDING MACHINE WITH SHUTTLE HOPPER Filed July 30, 1965Sheet 3 of 11 INVENTOR. Mum/1a 5 f2; 1. amr

March 18, 1969 H. E. FELLOWS 3,433,285

PNEUMATIC IMPACT-MOLDING MACHINE WITH SHUTTLE HOPPER Filed July 30, 1965Sheet 6 0f 11 INVENTOR.

A AAw/Jm/ 12'11 aw! Q w/ /hz M March 18, 1969 H. E. FELLOWS 3,433,235

PNEUMATIC IMPACT-MOLDING MACHINE WITH SHUTTLE HOPPER Filed July 30. 1965Sheet 8 of 11 lrrak/vi f.

March 18, 1969 H. E. FELLOWS 3,433,285

PNEUMATIC IMPACT-MOLDING MACHINE WITH SHUTTLE HOPPER Filed July so, 1965Sheet 9 of 11 INVENTOR. flue/raw in z or lrraz/vsn.

March 18, 1969 H. E. FELLOWS 3,433,285

PNEUMATIC IMPACT-MOLDING MACHINE WITH SHUTTLE HOPPER Filed July 30, 1965Sheet /0 of 11 March 18, 1969 H. E. FELLOWS PNEUMATIC IMPACT-MOLDINGMACHINE WITH SHUTTLE HOPPER Filed July 30, 1965 Sheet ll of 11 I NVENTQR. AQK/F/fd/Y .4: 21 L 0! I'll Y/ //A Y////1lV/ll II] III;

United States Patent 3,433,285 PNEUMATIC IMPACT-MOLDING MACHINE WITHSHUTTLE HOPPER Harrison E. Fellows, Clearwater Lake, Wis. 54518 FiledJuly 30, 1965, Ser. No. 476,090 US. Cl. 164-193 Int. Cl. B22c /12, 15/228 Claims ABSTRACT OF THE DISCLOSURE This invention relates to apneumatic impact-molding machine.

Sand from a suitable source is transferred by a reciprocable shuttlehopper to a magazine to which the hopper can be sealed under pressureduring the refilling of the hopper. This prevents leakage when the sandin the magazine is subjected to the amount of air pressure required forpneumatic impact transfer from the magazine into the mold or core boxcavity. In the preferred embodiment, the pressure which seals theshuttle hopper carriage to the magazine is applied only when the hopperregisters with the magazine and is relieved preliminary to the movementof the hopper toward the source.

With the magazine full of sand received from the shuttle hopper andclosed by the hopper, the magazine is subjected to air pressure. A spoolvalve controlling the air supply to the magazine permits a single valveto function in its respective advanced and retracted positions tocontrol both inlet and exhaust and to obtain rapid action with arelatively small-bore operating piston. For covering a large mold area,a number of such magazines can be used, all actuated from the same spoolvalve.

While the magazine will deliver and pack sand into a conventional mold,in the preferred embodiment the sand is packed into a molding chamber ina flaskless molding unit which has downwardly tapered fixed sides andmovable ends comprising compression rams which are operable between saidsides to further compact the sand. The downward taper of the sides ofthe molding chamber permits the finished mold to be withdrawn downwardlyfrom between the compression rams after the latter have been retracted.As each successive mold section is withdrawn, it is advanced in contactwith the preceding section, all being maintained at precisely the samelevel and guided between lateral confining plates to a pouring positionwhere the friction of such plates on the sections maintains a sealbetween the mold sections (with a minimum of sections on both sides ofthe pouring station) so that they will resist hydrostatic pressure ofmolten metal poured into the successive molds at the pouring station.

In order to permit cores to be set without interfering with thefunctioning of the machine, it is preferred that each successive moldsection be transferred to a core setting station from which it is thenadvanced on the pouring line. Since the core setting station is offsetfrom the line upon which the sections are advanced after being loweredfrom the molding chamber, the setting of cores does not interfere withadvance of the next section.

ice

In the drawings:

FIG. 1 is a fragmentary view in side elevation of one embodiment of myinvention.

FIG. 2 is a detail view partially in side elevation and partially inlongitudinal section through the apparatus shown in FIG. 1.

FIG. 3 is a view similar to FIG. 2 showing the parts in differentposition.

FIG. 4 is an enlarged fragmentary detail view in transverse sectionthrough the molding chamber.

FIG. 5 is a view taken in section on the line 55 of FIG. 1.

FIG. 6 is a view taken in section on the line 66 of FIG. 3.

FIG. 7 is a view taken in section on the line 77 of FIG. 3.

FIG. 8 is a detail view taken in section on the line 8-8 of FIG. 7.

FIG. 9 is a view similar to FIG. 1 showing a modified embodiment of theinvention.

FIG. 10 is a fragmentary detail view taken in cross section on the line10-10 of FIG. 9.

-FIG. 11 is a view partially in plan and partially in horizontal sectionon the line 1111 of FIG. 9.

FIG. 12 is a detail view in cross section on the line 1212 of FIG. 11.

FIG. 13 is a view similar to FIG. 1 showing another modified embodimentof the invention.

FIG. 14 is a view taken partially in plan and partially in section onthe line 14--14 of FIG. 13.

FIG. 15 is an end elevation on the line 1515 of FIG. 13.

FIG. 16 is a view taken in section on the line 1616 of FIG. 13.

FIG. 17 is a view taken in section on the line 1717 of FIG. 18.

FIG. 18 is a view taken in section on the line 1 818 of FIG. 17.

FIG. 19 is a view showing a modified pattern of slots in a sand guide,the viewpoint being similar to that of FIG. 18.

FIG. 20 is a fragentary view taken in horizontal section through thespool valve and a series of pressure magazines to and from which thespool valve controls air pressure admission and exhaust.

Referring, first, to the embodiment shown in FIGS. 1 to 4, the funnelshaped member 24 constitutes for the purposes hereof a source of moldingsand. The shuttle hopper 26 reciprocates from a first position of fullregistry with the source 24 as shown in FIG. 3 to a laterally offsetposition as shown in FIG. 2 in which the shuttle hopper discharge port28 registers with the pressure magazine 30. Movement of the shuttlehopper is effected by means of the ram piston 32 having a cylinder 34. Askirt 36 on the shuttle hopper closes the source when the shuttle hoppermoves from the FIG. 3 position to the FIG. 2 position. Details of theshuttle hopper 26 will be seen in FIG. 7, it being noted that the hopperis mounted on or is part of a carriage 38 having rollers 40 guided uponrails 42, the latter being adjustable as best shown in FIGS. 7 and 8.

Shuttle hopper carriage 38 is supported by a plate 44 which is aperturedover the magazine 30, the aperture registering with collar 46 whichdepends into the magazine 30 and is spaced both radially and axiallyfrom the upper end of the magazine 30 as clearly appears in FIG. 3. Whenthe transfer hopper registers with the magazine, the sand falls from thetransfer hopper into the magazine. In this position the top opening ofhopper 26 is still partially open to the source 24 as shown in FIG. 2,to permit flow of sand from the main source should there not be enoughsand in hopper 26 to fill the magazine 30. On the 3 return stroke backto the position of FIG. 3, the top of the magazine is completely closedby the bottom wall 47 of the carriage 38. This wall preferably hasinlaid into it a packing or sealing means such as an O-ring 49. Whenthis packing registers with the magazine, the cam 48 is actuated by theram 50 to press the wall to plate 44, whereby to completely seal themagazine over the sand therein.

Surrounding the magazine is a pressure housing 52 into and from whichair is admitted and exhausted subject to the control of a spool valve 54actuated by ram piston 56. In the position of the parts shown in FIG. 6,section 58 of the valve 54 is in registry with the port 62 of themagazine. Valve section 58 communicates with exhaust holes 52 openingthe magazine to the atmosphere. When the ram piston 56 moves the valvesection 60 into registry with port 64 of the pressure source, it alsoregisters with port 62 of the magazine to admit pressure to themagazine.

When spool valve section 60 registers with port 64 of the air reservoirand port 62 of the magazine, air will be admitted into the magazine 30to flow between the upper end of the magazine 30 and the dependingcollar 46, whereby the pressure is imposed on the top of the sand in themagazine to expel the sand vigorously through the tapered dischargethroat 68 of the magazine into a mold, or into the mold chamberpresently to be described. It is very desirable that this have inwardlycurved sides as shown. The sand flows better than as if the walls werestraight.

Also, it is preferred to have a thin plate 69 with a small opening tobreak up the sand as it enters the mold chamber. This is supported by abottom wall plate 72. The plates 69 and 70 may both be interchangeableso that the pattern of openings formed therein can be used to controlthe fiow and distribution of the sand in the mold or mold chamber.

A preferred mold chamber is shown in longitudinal section in FIG. 3 andin transverse section in FIG. 4. Its sides comprise a pair of foraminousplates 74 which are downwardly divergent as best shown in FIG. 4. Thesedesirably are provided with interchangeable liners at 76. The side Walls74 are preferably reinforced by ribs 75, which carry bearing bosses 77engagaging guide rods 79 for centering the mold chamber. To the centerribs are connected outwardly convex plates 78 to define the air exhaustmanifolds 80 shown in FIG. 4. From these manifolds, the air dischargepipes 82 lead to any appropriate point of discharge.

The ends of the molding chamber are provided by the ram pressure heads84 and 86 which are respectively operated by the ram pistons 88 and 90having cylinders 92 and 94. The pressure heads 84 and 86, each of whichcarries a half of the pattern, fit snugly between the side walls 74 andthe liners 76, if any, and will serve to compress between the side walls74 the sand fill already compressed in the mold chamber by the impactwith which it has been driven into such chamber by the air pressure inthe magazine 30. Parenthetically, it may be remarked that, as alreadyindicated, the magazine 30 may be used, if desired, to fill conventionalmolds rather than merely to fill a mold chamber such as that hereindescribed.

Assuming that the device includes a mold chamber rather than a mold, thebottom of such chamber may be made either by the elevator ram table 96on the elevator ram 98, as in FIG. 2, or I may use at the bottom of themold chamber a slide plate such as that shown at 100 in FIGS. 15 and 16.Particularly when there is no such plate and the sand surface of theresulting mold is to slide across a table of any sort, precise registryof the elevator table 96 with the receiving table is desired and,accordingly stops are provided at 102 which can be so adjusted that theelevator table 96 will register exactly with the fixed receiving tablesurfaces 104 onto which the finished mold shown in FIG. 2 at .106 is tobe delivered.

Upon compression of the sand in the mold chamber, the pressure heads 84,86 are retracted. This motion draws the pattern halves 110, 112, 114from the mold. Thereupon the elevator ram 98 lowers the finished mold toa level such that it clears the molding chamber and ram assembly. Toassist in freeing the finished mold from the sides of the mold chamber,a regulated back pressure of air is applied to the vents as the finishedmold is lowered. A pusher 107, operated by ram 108, then slides thefinished mold section from the elevator table 96 to the receiving table104.

As best shown in FIG. 3, any desired patterns such as the male patternand the complementary female pattern 112 may be attached to the pressureheads 84, 86, along with the smaller patterns 114 used to form thepouring cups. As the finished sand molds 106 are moved by pusher 107away from the molding area on the receiving table 104, they are in tightface contact, each successive section advancing under the pressure ofthe discharge ram head 107 being pressed against and serving to advancethe mold section preceding it. The pouring cup notches formed by molds114 will now register to provide cooperatively the pouring openings seenat 116 in FIG. 5.

The arrangement thus far described makes no provision for insertingcores. If cores are to be inserted, it is necessary in the device thusfar described to stop the moulding press for this purpose. In order togive ample time for inserting cores without interfering with theoperation of the press, it is preferred that each finished mold sectionbe moved laterally from the path on which it is delivered from themolding chamber, thus making room for immediate delivery of another moldsection from the chamber. Meantime, the laterally delivered section hasa brief period of dwell in a location wherein cores can be inserted andit is then propelled from that location in a direction which is parallelto the original path of delivery from the molding chamber. In itsmovement along said last mentioned path, it propels previously completedand cored mold sections under pressure (attributable to frictionalresistance), the resultant pressure holding the several sections tightlyengaged to receive molten metal.

The invention contemplates that the finished mold sections may besupported for the above described transverse motion upon a sectionaltable conveyor or, alternatively, they may be provided in the moldingchamber with supporting trays upon which they will be lowered from themolding chamber onto the cross conveyor, delivered by the cross conveyorto the coring station; and thence propelled upon the discharge path inwhich the pouring occurs.

Assuming that the trays are not to be used, the mold section will belowered from the mold chamber on the ram table 96 when the ram plunger98 is retracted to the position shown in dotted lines in FIGS. 1 and 9.Desirably, stops will be used as indicated diagrammatically at 118 inFIG. 9 so that the lowered table 96 will stop in precise registry withthe transfer flange 120 across which the mold will be pushed by head 122of ram 124 (FIGS. 1 and 9) onto the sectional conveyor table 126.

As best shown in FIG. 10, the various sections 128 which comprise thistable are mounted on arms 130 that project from the links of chains 132operating over appropriate sprockets, one of which is shown at 134 inFIG. 10. Together the several sections 128 provide a smooth andsubstantially continuous surface on the hori zontal run of the conveyorso that the finished mold sections 106 as received thereon are propelledlaterally with respect to the path of delivery from the mold. It will beunderstood that the conveyor operates only intermittently followingreceipt of a mold section. It delivers successive sections 106 intoregistry with the discharge table 138. During the ensuing dwell, while anew section is being received from the molding chamber onto the conveyor126, the previously delivered section shown at 106' in FIG. 11 will bedischarged from the conveyor 126 by the ram head 140 onto the table 138.Here, any desired cores 142 can be placed in positions where they willbe received into the openings provided in the complementary face of thenext arriving section.

The respective sections have complementary channels 144 and 146 which,as the several sections are assembled on table 138, are made to registerwith each other to form the pouring openings 150 (FIG. 11).

Theassembled sections have step-by-step movement along table 138 towarda pouring station, all of the sections being advanced on such table eachtime the ram 140 is operated. The friction of the foremost sectionsoffers sufiicient resistance to the stepped advance under pressure ofensuing sections so as to assure the tight engagement of thecomplementary faces of the sections about the cores and cavities. Ifdesired, the friction be tween the sections and the table 138 may beaugmented, and the several sections guided, by means of lateral confining plates 152 and 154 which are guided by arms 156 and 158 as shownin FIG. 12. Spring bias (springs not shown) may be provided if desired.

As already indicated, the invention contemplates the optional use oftrays 100 which serve as bottoms for the mold and support the molds ormold sections successively formed therein. FIGS. 13 and 16 show anarrangement in which the tray 100 partially closes the bottom of themold chamber and is supported on a conformed carrier 160. The carrier160 has vertically reciprocable guides at 162. It is operated by ram 163between its elevated full line position and its lowered dotted lineposition.

The rest of the mold chamber bottom is closed by hinged plates 161actuated by toggle links 164 operated by rams 166. These plates lockcarrier 160 in place against the pressure forcing the sand into the moldchamber. The plates 161 are retracted when the carrier 160 supportingthe tray 100 is lowered through the cross conveyor 170.

A tray 100 which is mounted on the carrier, and supports a mold section,is deposited on the conveyor when the carrier passes downwardly throughthe conveyor. The conveyor thereupon advances one step to bring an emptytray into registry with the carrier to be picked up by the next upwardmovement of the ram 163 to reclose the bottom of the molding chambertogether with plates on toggle links 164 and to receive another moldsection (FIGS. 14 and 15). Thus, the up and down movement of the carrier160 alternates with the step by step movement of the conveyor 170, eachvertical reciprocation of the carrier in a downward directiontransferring a finished mold section to the conveyor; each movement ofthe conveyor removing the finished mold section and advancing an emptytray into registry with the carrier; and each upward movement of thecarrier moving the empty tray into position to close the bottom of themolding chamber.

It will be understood that the device herein disclosed will be equippedwith pressure switches, limit switches and the like, which do notrequire illustration here since it is well within the skill of the artto provide these in the light of the following description of theoperating sequence.

Operating sequence When the machine is idle, the shuttle hopper will beopen, the magazine vent valve will be open, the ram pistons 88 and 90 atthe ends of the molding chamber will be advanced to close the moldingchamber for filling. All other rams will be retracted and all solenoidsde-energized.

The operator will initiate operation, preferably automatic, byenergizing the solenoid of a spring-centered valve to raise the elevatorram table for closing the mold chamber bottom. This operation will alsoenergize the solenoid of a 4-way valve to advance the shuttle hopperinto registry with the magazine where it will contact the limit switchto energize the solenoid of a 4-way valve which actuates the clamp forpressing the shuttle hopper to the magazine.

A pressure switch responsive to pressure in the elevator ram 98 (andhaving interlocked limit switches closed only when the mold forming ramheads 84 and 86 are in molding position and the hopper is closed) willenergize a circuit controlled by a timer. By means of this circuit, thesolenoid of a 4-way valve will be energized to open the spool valve 54to apply pneumatic pressure abruptly to the column of sand in themagazine for delivering the sand under high impact pressure into themold chamber. At the conclusion of the period fixed by the timer, thissolenoid will be de-energized to close the valve and the mold-formingrams 88 and '90 will be advanced from their initial positions tocompress the charge of sand impacted in the mold chamber. The ram heads84 and 86 are already in position to close the chamber as determined bylimit switches adjustable so that they can be set by the operator asrequired for each pattern. The amount of pressure in the cylinders 92and 94 will determine the hardness to which the mold section will becompressed in the chamber.

The circuit energizing the solenoid of the spool valve will alsoenergize the'solenoid of another timer which will determine the periodfor which compression of the mold by the heads 88 and 90 will bemaintained.

When final pressure has been reached in the ram cylinders 92 and 94,pressure switches which are in series and respectively connected to beoperated by the pressure of these cylinders will energize a pair of2-way valves to transfer hydraulic pressure through a restricted bypassto the ram cylinders 92 and 94 to exert this pressure in a retractingdirection upon the pistons 88 and 90 in a withdrawal direction to effecta slow draw. After initial slow movement has freed the pressure headsfrom the work, a timer will de-energize these solenoids and divert thehydraulic pressure to effect rapid withdrawal of the heads for theremainder of their retraction strokes. At the ends of the retractionstrokes, limit switches will be used to de-energize the controllingsolenoids of the respective valves so that the retractive movement ofthe ram pressure heads will terminate.

One of these switches may also be used to de-energize the solenoid ofthe valve which caused the hopper to move into registry with themagazine. The other such switch will energize through a timer, thesolenoid of a valve which applies air pressure to the several vents.These two switches in series will energize the valve which controls theelevator ram to initiate the lowering of the completed mold section.

At this point the elevator ram is automatically energized to lower theelevator and thereby to withdraw the mold from the molding chamber. Thestop above described will determine the extent of such movement and ator about the point at which the elevator engages the stops, a limitswitch will be contacted to return the ram pressure heads 84 and 86 totheir original intermediate positions from which they will advance onlyafter a further batch of compacted sand has been delivered into themolding chamber thus closed by them. Limit switches will stop the ramswhen the pressure heads reach these intermediate positions.

The limit switch energized by the elevator in its fully retractedposition will also energize the solenoid of a 4-way valve which effectsoperation of ram 108 to transfer the finished mold to the pouring line.Concurrently, it will de-energize the solenoid of the spring-centeredvalve controlling the elevator. When the shuttle hopper reaches registrywith its source and receives sand therefrom, a limit switch engaged bythe shuttle hopper will return it into registry with the magazine, whereit will dwell pending initiation of a new cycle. If the device is setfor automatic operation, and the general control switch is closed, thenew cycle will commence automatically when the ram controlling theshuttle hopper contacts a limit switch engaged when the shuttle hopperregisters with the magazine.

I claim:

1. In a pneumatic impact-molding machine, the combination with a moldingchamber, and a magazine for delivering sand into the molding chamber,and a source of sand offset from the magazine; of a shuttle hoppermounted for movement transversely of the magazine between a position ofregistry with the source and a position of registry with the magazine,means for sealing the magazine while the shuttle hopper is in registrywith the source, and means operative while the shuttle hopper registerswith the source for admitting a pneumatic fluid under pressure to thesealed magazine for the impact filling of the molding chamber with sandpreviously delivered to the magazine from the shuttle hopper.

2. A pneumatic impact-molding machine according to claim 1 in which themolding chamber comprises sides, ram heads fitted between said sides andguided for movement between retracted and advanced positions throughintermediate positions wherein the heads constitute end walls for saidchamber, rams connected with said heads for advancing and retracting theheads, and retractable means for closing the bottom of the moldingchamber between the side walls and said ram heads.

3. A pneumatic impact-molding machine according to claim 2 in which saidsides of the molding chamber are downwardly divergent.

4. A pneumaic impact-molding machine according to claim 1 in which themeans for closing the bottom of the chamber comprises an elevator havingmeans for raising and lowering said bottom closing means between a firstposition in which the molding chamber is closed and a second position inwhich a mold formed in said chamber is Wholly removed to a level belowthe level of the chamber.

5. A pneumatic impact-molding machine according to claim 4 in which theclosing means comprises a tray for the support of a molded article andwhich is removably connected with said elevator means.

6. A pneumatic impact-molding machine according to claim 5 in furthercombination with means for propelling laterally from said elevator meanssuccessive articles lowered by said elevator means from said chamber.

7. A- pneumatic impact-molding machine according to claim 6 in furthercombination with a conveyor having openings through which said elevatormeans is advanced upwardly and retracted downwardly, the mold supportingtray being engageable with said conveyor to be supported thereon whenthe elevator means is retracted through the conveyor, said conveyorconstituting the means for laterally propelling the mold.

8. A pneumatic impact-molding machine according to claim 1 in which athroat provides communication between the magazine and the moldingchamber, said throat having side walls inwardly convex toward each otherfor guiding the flow into the molding chamber.

References Cited UNITED STATES PATENTS 3,303,535 2/1967 Rearwin et al164-213 X 3,327,767 6/1967 Wallwork 164-28 382,003 5/1888 Kirker137-625.69 2,778,598 1/1957 Bolling 2S1- 63 2,951,260 9/1960 Harrison etal 18-30 2,986,785 6/1961 Mitler et al. 16438 3,008,199 11/1961 Jeppesen164-22 3,088,854 5/1963 Spies 239-601 3,273,207 9/1966 Taccone 164--2103,292,216 12/1966- Colombo 249158 956,638 5/1910 Hotter 249129 1,595,6008/1926 Demmler 164200 2,243,092 5/1941 Eteau 164-193 2,607,967 8/1952Springer 164200 2,640,234 6/1953 Bergami 164193 2,702,417 2/ 1955Peterson 164201 2,783,509 3/1957 Miller 164-200 3,089,205 5/ 1963 Ellms164-202 3,089,206 5/ 1963 Abraham 164-200 FOREIGN PATENTS 623,388 7/1961 Canada.

1,159,596 12/1963 Germany.

I. SPENCER OVERHOLSER, Primary Examiner.

ROBERT D. BALDWIN, Assistant Examiner.

US. Cl. X.R.

